new engine and the accompanying tranny plus an ecu that will work with said engine also cutting the frame to make room to connect the tranny with the differential also you need to make room for a differential you might not even have all the luxuries like air conditioning and power steering and if you want them then they have to be compatible with your engine like everyone says anything is possible with money and time and someone willing to do something this complicated just buy an s if you really want a rwd honda